Electron scattering by Se XXV (neon-like selenium) using the Dirac R-matrix method

The Dirac R-matrix method has been used to calculate collision strengths for the scattering of electrons with kinetic energy 100-300 Ryd by a neon-like selenium (Se 24+ ) target. In these calculations the 27 jj-coupled levels arising from the configurations 1s 2 2s 2 2p 6 , 1s 2 2s 2 2p 5 3s, 1s 2 2s 2 2p 5 3p and 1s 2 2s 2 20p 5 3d are included. Collision strengths converged to within 5% are obtained with twenty-four (N+1)-particle collision symmetries (partial waves). The rates for radiative transitions between the 27 levels have also been calculated. The authors' results are compared with previous calculations.